The pace of enrollment is expected to accelerate in coming days, with the approach of the Dec. 15 deadline for selecting a HealthCare.gov plan that goes into effect Jan. 1. Most of the 11 states that operate their own Obamacare marketplaces have later deadlines.

Despite the likelihood of enrollment picking up this week, there is still a serious risk that HealthCare.gov will fall short of last year’s enrollment tally of 9.2 million people.

Last year, from Nov. 1 through Dec. 10, almost 4.02 million people had selected a plan on HealthCare.gov, according to the Centers for Medicare and Medicaid Services.

The enrollment snapshot that CMS released Wednesday, which shows 3.6 million sign-ups since the beginning of November, covers a period that is eight days shorter.

Given the current pace of enrollments, it is likely that next week’s tally will beat the total seen during the same time frame last year.

But Obamacare advocates are worried that the final tally for this season will be lower than last year’s, due to several factors.

They note that this year’s enrollment period is half the length of last year’s season. Many consumers are unaware of that fact.

Another concern among advocates is that repeated negative comments about Obamacare by the Trump administration will discourage many people from signing up for coverage.

The administration also has slashed the budgets for outreach and advertising promoting enrollment in Obamacare plans.

If people do not sign up for some form of health insurance by the end of December — such as an Obamacare plan, a job-based health plan, Medicare or Medicaid — they risk being subject to the tax penalty.

However, Congress is currently considering tax legislation that would suspend that Obamacare penalty for not having some form of health insurance.

If the penalty does not end up being suspended, uninsured people face a potential fine that is the higher of $695 per adult or 2.5 percent of household income.

Most Obamacare customers qualify for financial aid that can lower their monthly insurance premiums, often dramatically. Many Obamacare customers also qualify for discounts to their out-of-pocket health charges when they obtain medical services or prescription drugs.